Breast Anatomy Beyond the Nipple

2019-07-18T13:29:10+00:00July 18th, 2019|Categories: Fertility Blog|Tags: , , , , |

The internal structures of breasts were first described in 1840 by Sir Astley Cooper. And since then, our knowledge of breasts has changed to include many more than Cooper could have visualized. He described the breast being composed of glandular and adipose (fat) tissue held together by a loose framework of fibers he called Cooper’s ligaments (of course). Cooper’s ligaments support the structure of our breasts and are blamed for stretching during pregnancy and breastfeeding, leading to sagging. If you are interested, there are several exercises that claim to strengthen Cooper’s ligaments. I reviewed them and it appears they work the pectoral muscles (push ups, chest flys and chest press) which lay under your breasts. Working out your pectoral muscles helps your posture but is unlikely to have an impact on the connective tissue inside the breast.


Beyond the ligaments, the inside of a breast is an amazingly complicated structure. Surrounding the nipple like daisy petals are 15 to 20 sections, or lobes. Inside these lobes are smaller sections, called lobules that are arranged in clusters, like grape bunches. At the end of each lobule are tiny “bulbs” that produce milk. The bulbs are called alveoli and that’s where the magic of milk production occurs. From the alveoli,your milk enters the ducts, the thin tubes that carry the milk from the lobules to the nipple. When the milk-ejection reflex occurs, small muscles around the alveoli are squeezing the milk out into the lobules to the ducts and out of the nipples.


Imagine a stalk of broccoli and the tiny flower bits are the alveoli, the stem is the ducts which carry the milk to the nipple. Fat fills the spaces between the lobes and ducts. Actually, most of our breast volume is fat. When you shop for a bra, your cup size is mostly determined by how much fat you have between your connective tissue. That’s why your cup size has no relation to your ability to breastfeed. Smaller breasts (A to C cups) can be easier for babies to latch on, especially in the first days of life.


Working our way out of the breast, the last stop is the nipple. The nipple is in the center of a dark area of skin called the areola. The areola contains small glands that lubricate the nipple during breastfeeding. The bumps on the perimeter of your nipple are glands called Montgomery glands. They constantly secret oil to keep your areola and nipple healthy and moisturized. Montgomery glands also secret your unique scent that attracts your baby to the nipple and helps initiate breastfeeding. We have 12-14 openings in each nipple, and they can spray in any direction as anyone that his squirted milk in unpredictable directions knows.